Field of the Invention
The invention relates to a heater with a housing with a fluid channel, disposed therein, with a fluid inlet and a fluid outlet, whereby a coil which generates an alternating magnetic field and is separated sealed from the fluid channel by a coil housing, is provided in the housing, whereby at least one metallic flat heating element is provided, which can be heated by the alternating magnetic field, whereby the at least one flat heating element is disposed in the fluid channel.
Description of the Background Art
Additional heaters, which provide heat to the interior independent of the heat output supplied by the internal combustion engine or in addition to it, are increasingly needed for heating vehicles, particularly in vehicles with low-consumption internal combustion engines or in hybrid vehicles.
Electrically powered heaters have proven especially practical in this case. These provide the necessary heat rapidly and can be dimensioned as especially space-saving. So-called high-voltage heaters, which can be operated at a voltage of over 300 volts, are suitable in particular for use in hybrid vehicles.
Heaters are known from the conventional art. Thus, there are air-side heaters, which have so-called PTC heating elements, which are supplied with electric current and are heated thereby. The heat is transferred to the circulating air via air-side ribs, which are in contact with the PTC elements. These heaters, however, have a basically different structure than is necessary for liquid media.
Heaters for liquid media are provided with a closed housing, which are formed with a fluid channel with a fluid inlet and a fluid outlet, whereby a heating element heated with a PTC element projects into the housing.
The heaters for liquid media have the disadvantage that the heat is produced in a region different from the fluid channel through which the liquid medium to be heated flows. As a result, because of the present transfer resistances a delayed heating is achieved, which is to be regarded as disadvantageous.
The disadvantage of the solutions in the conventional art in particular is that the efficiency of known heaters is low and the structure is very complex.